cp_hashtable

Section: libcprops - cp_hashtable (3)
Updated: OCTOBER 2005
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NAME

cp_hashtable - a general purpose hashtable implementation

DESCRIPTION

cp_hashtable is a general purpose hashtable implementation. Instances may be created with a specifiable degree of internal or external synchronization and entry memory management. It is also possible to specify the load factors controlling when internal table resizes occur.

INTERFACE

the following is a summary of functions provided by <cprops/hashtable.h>.

CONSTRUCTOR FUNCTIONS

cp_hashtable *cp_hashtable_create(long initial_size,
                                   cp_hashfunction hash_fn,
                                   cp_compare_fn compare_fn);
cp_hashtable *cp_hashtable_create_by_mode(int mode,
                                           int initial_size,
                                           cp_hashfunction hash_fn,
                                           cp_compare_fn compare_fn);
cp_hashtable *
      cp_hashtable_create_copy_mode(long initial_size,
                                    cp_hashfunction cp_hashfn,
                                    cp_compare_fn compare_fn,
                                    cp_copy_fn copy_key,
                                    cp_destructor_fn free_key);
                                    cp_copy_fn copy_value
                                    cp_destructor_fn free_value);
cp_hashtable *
      cp_hashtable_create_by_option(int mode,
                                    long initial_size,
                                    cp_hashfunction hash_fn,
                                    cp_compare_fn compare_fn,
                                    cp_copy_fn copy_key,
                                    cp_destructor_fn free_key);
                                    cp_copy_fn copy_value
                                    cp_destructor_fn free_value);

DESTRUCTOR FUNCTIONS

void cp_hashtable_destroy(cp_hashtable *table);
void cp_hashtable_destroy_shallow(cp_hashtable *table);
void cp_hashtable_destroy_deep(cp_hashtable *table);
void cp_hashtable_destroy_custom(cp_hashtable *table,
cp_destructor_fn dk,
cp_destructor_fn dv);

ITEM INSERTION

void *cp_hashtable_put(cp_hashtable *table, void *key, void *value);
void *cp_hashtable_put_by_option(cp_hashtable *table, void *key,
                                  void *value, int mode);
void *cp_hashtable_put_safe(cp_hashtable *table, void * key,
                             void *value);
void *cp_hashtable_put_copy(cp_hashtable *table, void *key,
                             void *value);

ITEM RETRIEVAL

void *cp_hashtable_get(cp_hashtable *table, void *key);
void *cp_hashtable_get_by_option(cp_hashtable *table, void *key,
int mode);
void **cp_hashtable_get_keys(cp_hashtable *table);
void **cp_hashtable_get_values(cp_hashtable *table);
int cp_hashtable_contains(cp_hashtable *table, void *key);

ITEM REMOVAL

void *cp_hashtable_remove(cp_hashtable *table, void *key);
int cp_hashtable_remove_deep(cp_hashtable *table, void *key);
int cp_hashtable_remove_all(cp_hashtable *table);

BEHAVIOR

int cp_hashtable_set_mode(cp_hashtable *table, int mode);
int cp_hashtable_unset_mode(cp_hashtable *table, int mode);
int cp_hashtable_set_min_size(cp_hashtable *table, int size);
int cp_hashtable_set_min_fill_factor(cp_hashtable *table, int factor);
int cp_hashtable_set_max_fill_factor(cp_hashtable *table, int factor);

SYNCHRONIZATION

int cp_hashtable_lock(cp_hashtable *table, int type);
int cp_hashtable_unlock(cp_hashtable *table);
int cp_hashtable_rdlock(cp_hashtable *table);
int cp_hashtable_wrlock(cp_hashtable *table);

OTHER

long cp_hashtable_count(cp_hashtable *table);
cp_hashtable_is_empty(cp_hashtable *table);

HASH- and COMPARISON FUNCTIONS

libcprops provides the following hash function implementations for primitives and null terminated strings:

long cp_hash_char(void *key);


int cp_hash_compare_char(void *a, void *b);


long cp_hash_int(void *key);


int cp_hash_compare_int(void *a, void *b);


long cp_hash_long(void *key);


int cp_hash_compare_long(void *a, void *b);


long cp_hash_float(void *key);


int cp_hash_compare_float(void *a, void *b);


long cp_hash_double(void *key);


int cp_hash_compare_double(void *a, void *b);


long cp_hash_addr(void *key);


int cp_hash_compare_addr(void *a, void *b);


long cp_hash_string(void *key);


int cp_hash_compare_string(void *a, void *b);


long cp_hash_istring(void *key);


int cp_hash_compare_istring(void *a, void *b);

EXAMPLE

The following code creates a hashtable mapping names to phone numbers. The hash function used is cp_hash_istring, a case insensitive hash function for null terminated strings.

#include <stdio.h>
#include <string.h>             /* for strdup */
#include <strings.h>    /* for strcasecmp */
#include <stdlib.h>             /* for free */
#include <cprops/hashtable.h>

int main()
{
    cp_hashtable *t =
        cp_hashtable_create_by_option(COLLECTION_MODE_NOSYNC |
                                      COLLECTION_MODE_COPY |
                                      COLLECTION_MODE_DEEP,
                                      10,
                                      cp_hash_istring,
                                      (cp_compare_fn) strcasecmp,
                                      (cp_copy_fn) strdup,
                                      (cp_destructor_fn) free,
                                      (cp_copy_fn) strdup,
                                      (cp_destructor_fn) free);

    cp_hashtable_put(t, "ed", "123");
    cp_hashtable_put(t, "zed", "345");
    cp_hashtable_put(t, "fred", "789");

    while (1)
    {
        char name[80];
        char *number;

        printf("enter name [quit]: ");
        name[0] = '\0';
        fgets(name, 80, stdin);
        name[strlen(name) - 1] = '\0'; /* chop newline */
        if (name[0] == '\0') break;

        if ((number = cp_hashtable_get(t, name)) != NULL)
            printf("%s: %s\n", name, number);
        else
            printf("no entry for %s\n", name);
    }

    cp_hashtable_destroy(t);
    return 0;
}

for notes on compiling and linking see cprops(3).

Index

NAME

DESCRIPTION

INTERFACE

CONSTRUCTOR FUNCTIONS
DESTRUCTOR FUNCTIONS
ITEM INSERTION
ITEM RETRIEVAL
ITEM REMOVAL
BEHAVIOR
SYNCHRONIZATION
OTHER
HASH- and COMPARISON FUNCTIONS

EXAMPLE

SEE ALSO

This document was created by man2html, using the manual pages.
Time: 12:01:45 GMT, May 23, 2006